Internal combustion engines include or operate in conjunction with fuel tanks that store gasoline, diesel fuel, biofuels or other fuels prior to their consumption by the engines. A variety of different types of fuel tanks and methods of coupling/integrating those fuel tanks with internal combustion engines are known in the art. At least some conventional internal combustion engines employ plastic fuel tanks. In some such embodiments, the plastic fuel tank includes a boss feature molded into the plastic fuel tank that allows a fastening screw extending from the remainder of the engine (e.g., from the engine crankcase) to thread directly into the fuel tank body, thereby allowing direct fastening of the fuel tank to the remainder of the engine.
Notwithstanding the common usage of this type of design, there are at least two disadvantages with such a design. First, during factory assembly or field service of an engine employing such a configuration, it is possible that an improper screw may be threaded into the fuel tank boss. The fuel tank is then at risk from cracking and leaking if the screw diameter is too large or at risk from puncture and leakage if the screw is too long. Additionally, such a conventional design can risk cracking of the fuel tank due to fatigue experienced over time. In particular, forming the screw boss feature on the fuel tank can create an irregular wall thickness. When exposed to various types of stresses over time, particularly stresses associated with exposure of the fuel tank to fuel chemicals and various environmental effects including variations in the temperature to which the fuel tank is exposed, it is possible that the fuel tank may crack and begin to leak fuel. This situation can be exacerbated by material deformation of the screw.
At least some conventional plastic fuel tanks are manufactured via a blow-molding process. Although blow-molding is a useful process for manufacturing components such as fuel tanks, it is especially difficult to create detailed features such as bosses using this process. Consequently, with respect to blow-molded fuel tanks, other methods have often been used to constrain and mount fuel tanks, such as clamping of external web-sections. While such methods can avoid direct impregnation of the fuel tanks by fastening screws, such methods often involve extra cost burdens, for example, those associated with the use of additional clamping materials and the additional assembly time required to manufacture such fuel tank assemblies.
For at least these reasons, therefore, it would be advantageous if an improved fuel tank system and/or method of assembling fuel tanks to internal combustion engines could be developed. More particularly, it would be advantageous if, in at least some embodiments, the risk that portion(s) of the fuel tank and/or mounting component(s) allowing for the fuel tank to be fastened to the remainder of an internal combustion engine might result in damage to the fuel tank was reduced by comparison with conventional fuel tank systems. Additionally, it would be advantageous if, in at least some embodiments, advantage(s) associated with manufacturing a fuel tank by way of a blow-molding process could be achieved without incurring one or more of the constraints faced when implementing blow-molded fuel tanks in conventional engines.